title: Vitamin C further improves the protective effect of GLP-1 on the ischemia-reperfusion-like effect induced by hyperglycemia post-hypoglycemia in type 1 diabetes.
abstract: BACKGROUND
  It has been reported that hyperglycemia following hypoglycemia produces an ischemia-reperfusion-like effect in type 1 diabetes. In this study the possibility that GLP-1 has a protective effect on this phenomenon has been tested.
  
  
  METHODS
  15 type 1 diabetic patients underwent to five experiments: a period of two hours of hypoglycemia followed by two hours of normo-glycemia or hyperglycemia with the concomitant infusion of GLP-1 or vitamin C or both. At baseline, after 2 and 4 hours, glycemia, plasma nitrotyrosine, plasma 8-iso prostaglandin F2alpha, sCAM-1a, IL-6 and flow mediated vasodilation were measured.
  
  
  RESULTS
  After 2 h of hypoglycemia, flow mediated vasodilation significantly decreased, while sICAM-1, 8-iso-PGF2a, nitrotyrosine and IL-6 significantly increased. While recovering with normoglycemia was accompanied by a significant improvement of endothelial dysfunction, oxidative stress and inflammation, a period of hyperglycemia after hypoglycemia worsens all these parameters. These effects were counterbalanced by GLP-1 and better by vitamin C, while the simultaneous infusion of both almost completely abolished the effect of hyperglycemia post hypoglycemia.
  
  
  CONCLUSIONS
  This study shows that GLP-1 infusion, during induced hyperglycemia post hypoglycemia, reduces the generation of oxidative stress and inflammation, improving the endothelial dysfunction, in type 1 diabetes. Furthermore, the data support that vitamin C and GLP-1 may have an additive protective effect in such condition.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ceriello
authors.forename: Anna
authors.initials: A
authors.lastname: Novials
authors.forename: Emilio
authors.initials: E
authors.lastname: Ortega
authors.forename: Silvia
authors.initials: S
authors.lastname: Canivell
authors.forename: Gemma
authors.initials: G
authors.lastname: Pujadas
authors.forename: Lucia
authors.initials: L
authors.lastname: La Sala
authors.forename: Loredana
authors.initials: L
authors.lastname: Bucciarelli
authors.forename: Maurizio
authors.initials: M
authors.lastname: Rondinelli
authors.forename: Stefano
authors.initials: S
authors.lastname: Genovese
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000008:administration & dosage*; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D007003:Hypoglycemia / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007249:Inflammation / Q000097:blood / Q000517:prevention & control; D018836:Inflammation Mediators / Q000097:blood; D007263:Infusions, Parenteral; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D015427:Reperfusion Injury / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014443:Tyrosine / Q000031:analogs & derivatives / Q000097:blood; D014664:Vasodilation / Q000187:drug effects; D055815:Young Adult
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D001786:Blood Glucose; D007004:Hypoglycemic Agents; C573420:ICAM1 protein, human; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D018799:Intercellular Adhesion Molecule-1; C075750:8-epi-prostaglandin F2alpha; C002744:3-nitrotyrosine; D014443:Tyrosine; D052216:Glucagon-Like Peptide 1; D015237:Dinoprost; D001205:Ascorbic Acid